It is desirable, in the cooking process of certain food products, such as, for example, bakery products and pastries, to subject such products to a rotatory motion within the oven, in order that they may receive the heat uniformly and thus achieve a more homogenous cooking thereof.
In this sense, there are known ovens having a tray-carrying truck as an auxiliary element, in the trays whereof are placed the products to be cooked, the said truck being slidable to facilitate transport thereof, the oven including on its ceiling or upper walls suspension means for the said truck, which suspension means are further driven by a motor, such that once the tray-carrying truck has been duly established within the oven it is subjected to a constant rotatory motion during the cooking process.
One of such ovens is described, for example, in U.S. Pat. No. 3,595,178, priority of 1967.
The said U.S. patent specifically describes an oven having on its ceiling a rotating platform related to the shaft of a motor-reducer group, which platform is provided with bent flanges at its opposite edges, wherein are established respective pairs of rollers on which slide angular profiles which emerge upwards from the tray-carrying truck, such that this latter is suspended from the upper, rotating platform of the oven through the said angular profiles which rest on the said rollers, the rollers furthermore resulting in the elevation of the truck from the floor or base of the oven on being introduced thereinto, said truck thus being free to rotate on being dragged by the rotating platform.
Such a solution, though acceptable from an operative point of view, has, in practice, two important problems, first of all the means for receiving and suspending the tray-carrying truck considerably reduce the height of the oven chamber, in an amount of some 10 cm, wherefore a different solution would allow, in a certain type of oven, the use of a truck carrying one more tray. Furthermore, and likewise in accordance with the structure described, each oven may only receive a certain type of tray-carrying truck, thereby lacking the functional versatility which would allow the use of different sized trucks, this being necessary in many cases where different types of bakery products are manufactured in the same establishment.
Along these same lines is Spanish Utility Model No. 198.453 which, based on the same functional structure as the previously-described oven, has certain modifications basically centred in the substitution of the mentioned upper rotating platform for a hooked element which also allows the substitution of the previously-mentioned set of four rollers for a single roller, although in this case, and in order to prevent sideways balancing of the tray-carrying truck, a rotating guide to which may be coupled a shaft emerging vertically and centrally from the lower base of the tray-carrying truck must be provided on the floor or base of the oven. This solution simplifies the upper suspension means for the tray-carrying tuck, at the expense of a more complex lower part of the oven due to the presence of the said rotating guide, not provided in U.S. Pat. No. 3,595,178 mentioned before, and furthermore fails to solve the problems of the said patent, for the said suspension means for the tray-carrying truck are established between the top of the oven and the upper surface of the truck, thus taking up a considerable amount of space.